About 2.5 billion tons of nylon 6 is produced annually on a worldwide basis. The production of nylon 6 is accomplished by the ring opening polymerization of the monomer ε-caprolactam. The starting chemical compound for the production of ε-caprolactam is benzene which is converted to either cyclohexane or phenol and either chemical is converted via cyclohexanone to cyclohexanone oxime and then this intermediate is heated in sulfuric acid. This chemical reaction is known as the Beckman rearrangement. The starting chemical benzene is produced via the refinement of petroleum chemicals.